Diving Forest Elephants

Dateline: Kessala, Gabon  8 October 2011

Cantilevered out over the Mpassa River, the platform provides a wonderful view of a bend in the river and the sandbar surrounded by places for elephants to drink mineral water. From here we can see the ARU (autonomous recording unit) that we have used to monitor elephant activity over the last two years.

In most particulars this site is just like any other 'bai': mineral access, an opening where family units can meet and interact, a place where individuals can find mates. But different because it is a big river with a strong current. Last night a nice big male with heavy tusks was up to his hips in the river when we arrived. Over and over again he first squatted down, then apparently knelt on the river bottom in order to get his trunk down into a mineral pit. At times he was completely under, but his butt kept popping up and an occasional tail-twitch gave away his position. (I will put a video here when I get somewhere that can handle the upload!)

A bit later in the afternoon a female group arrived; two adult females each with a calf. On of these calves ws probably 7-8 years old, the other maybe about 4 years. Strange that there was not a very young calf with either female. The group materialized across the deep channel where the male was diving and immediately went into the river. They swam a bit, then the females got to a point where they could stand. The two calves kept going toward the middle of the river and the sand bar. I expect they didn't like fighting the current where their mothers stopped to drink - perhaps exhausting for them to hold their position against the current when their feet barely touched bottom and with their lighter bodies.

A few years ago Nicolas Bout, a colleague of mine here in Gabon, observed this 'diving' behavior and wrote a short note for publication, interpreting that the elephants were after minerals. Some reviewer of the note rejected this as unconfirmed so the note was refused. But my video clearly shows identical behavior sequences to elephants in typical forest clearings. The females were sometimes in shallower water where is was clear that they were on their knees (as often seen in the Dzanga clearing in Central African Republic), forcefully pushing trunks into the bottom of the river, blowing out air and then pausing. Then up to drink. I think I will have to join forces with Nicolas and submit the note again!

They Stick it to Elephants

Dateline: Franceville, Gabon 7 October 2011

Elephants. The biggest land mammal on earth. Forest elephants might not be quite the largest of the three species, but surely they are the most mysterious. How can something so big be so poorly known? I’m just back from a few days in the Precious Woods forestry concession north of Lastourville, Gabon. Five years ago we started recording elephant calls at several clearings within a day’s walk of Ivindo National Park, and one of these, we found, has more elephants visiting at some times of year than any other known location in Gabon. That time of year is now, and yet we didn’t see many animals. Is it all explained by a somewhat late start to the rainy season? Have we unwittingly changed the pattern of visitation by establishing a regular monitoring program here (it is a small opening and probably holds our scent like a brandy snifter holds alcohol fumes)? Is it because of logging activity in the area 18 months ago? What really drives these animals to visit clearings in the first place – or the second or third?

We did have a lovely male come in just a few minutes before dark, and with a waxing moon we had a tantalizingly lit stage before us, showing flowing shapes enough to know that others came after dark, although we could hear that well enough. Still the forest was relatively quiet in terms of pachyderms, and perhaps this explains the decidedly unquiet time I am having right now.

There is something else that populates the forests of Gabon, not so big, but likely keenly aware of when forest elephants are numerous and when they are not. This is the elephant tick – a tiny beast less than the diameter of a pin head. How this arachnid, so minute in size, can specialize as an ectoparasite on the tough, thick, skin of an elephant is perhaps a wonder of nature – but when elephants are scarce these little beasts find easy sustenance on Peter Wrege! Always I get some of these on me, part of what comes with working in rainforests with elephants. Unfortunately my reaction seems to be getting increasingly severe and sometimes the bites last as itchy welts for well over six months (the ticks themselves usually drop off on their own, perhaps in disgust at having attached to the wrong host). On this particular excursion we hiked to the bai and then slept there the night – no opportunity to limit the damage by washing away some of the attackers with an evening bath. So I’m covered now and not all that happy about it – I’m sure the ticks and I would both be happier with a few more elephants to focus on.